Mechanism of gene expression of Arabidopsis glutathione S-transferase, AtGST1, and AtGST11 in response to aluminum stress
Mechanism of gene expression of Arabidopsis glutathione S-transferase, AtGST1, and AtGST11 in response to aluminum stress
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DOI：
10.1104/pp.103.037135
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发表时间：
2004-04-01
期刊：
影响因子：
7.4
通讯作者：
Matsumoto, H
中科院分区：
文献类型：
--
作者：
Ezaki, B;Suzuki, M;Matsumoto, H
分析铝诱导的两个拟南芥谷胱甘肽S-转移酶基因AfGST 1和AtGST 11的基因表达，以探讨铝胁迫响应的机制。将每个基因的5 ′上游区的约1-kb DNA片段与β-葡糖醛酸酶（GUS）报告基因（pAtGST 1：：GUS和pAtGST 11：：GUS）融合，并导入拟南芥生态型兰茨贝格直立。所构建的转基因株系在铝胁迫下表现出不同程度的根和/或叶中基因表达的时间依赖性。pAtGST 1：：GUS基因在短时间Al处理后诱导（暴露2小时后最大表达），而pAtGST 11：：GUS基因通过较长时间Al处理诱导（最大表达约8小时）。由于铝胁迫下只有根在叶片中表达，因此铝胁迫下根与地上部之间可能存在信号传导系统。使用携带pAtGST 11：：GUS基因的成体转基因株系的GUS染色实验支持这一建议。此外，Al处理的同时，在根区的各种钙耗尽条件下增强了pAtGST 11：：GUS基因在地上部的表达。这一结果表明，根中铝毒的程度反映了pAtGST 11：：GUS在地上部中通过推导的信号系统的基因响应。这两个转基因株系在低温胁迫、高温胁迫、金属毒害和氧化损伤后GUS活性也有所提高，表明它们对铝胁迫等逆境胁迫有共同的诱导机制。
The gene expression of two Al-induced Arabidopsis glutathione S-transferase genes, AfGST1 and AtGST11, was analyzed to investigate the mechanism underlying the response to Al stress. An approximately 1-kb DNA fragment of the 5'-upstream region of each gene was fused to a beta-glucuronidase (GUS) reporter gene (pAtGST1::GUS and pAtGST11::GUS) and introduced into Arabidopsis ecotype Landsberg erecta. The constructed transgenic lines showed a time-dependent gene expression to a different degree in the root and/or leaf by Al stress. The pAtGST1::GUS gene was induced after a short Al treatment (maximum expression after a 2-h exposure), while the pAtGST11::GUS gene was induced by a longer Al treatment (approximately 8 h for maximum expression). Since the gene expression was observed in the leaf when only the root was exposed to Al stress, a signaling system between the root and shoot was suggested in Al stress. A GUS staining experiment using an adult transgenic line carrying the pAtGST11::GUS gene supported this suggestion. Furthermore, Al treatment simultaneously with various Ca depleted conditions in root region enhanced the gene expression of the pAtGST11::GUS in the shoot region. This result suggested that the degree of Al toxicity in the root reflects the gene response of pAtGST11::GUS in the shoot via the deduced signaling system. Both transgenic lines also showed an increase of GUS activity after cold stress, heat stress, metal toxicity, and oxidative damages, suggesting a common induction mechanism in response to the tested stresses including Al stress.